The SRO mic (later renamed TC20) is one of the very few
truly omnidirectional mics. There is no audible timbral or volume
change in any orientation to the sound source. The sound is
utterly neutral, with no coloration at all. These mics shine in
capturing concert hall acoustics.

The ultra-smoothness and ultra-fast transient response of
the SROs capture a "you are there" realism seldom realized
by other high-end mics.

Description:
Earthworks SRO is an omnidirectional (pressure) prepolarized condenser microphone directly coupled
to a dedicated wideband, low output impedance preamplifier. The SRO requires a standard 48V phantom power supply.
It features a linear free-field frequency response from 10Hz to 20kHz (Fig. 2), fast impulse response (Fig. 3), very low handling noise, uni-form polar pattern, and very high SPL handling capabilities.
It exhibits no proximity effect.

Applications:
Earthworks SRO is easy to operate. Connect the microphone to a microphone preamplifier supplying 48V phantom power using a standard XLR microphone cable. Please allow up to one minute for the microphone to settle. Plugging in the microphone “hot” (phantom power already present at the input) will not damage the microphone, and is actually preferred for faster settling. It is normal for any phantom powered mic to “pop” when plugged in or powered up. Make sure to mute the signal to speakers or headphones when phantom power is first applied.
The SRO is our least expensive general-purpose omni. It is a good choice for close-miking louder sources such as instrument amps, drums, or close-miked brass. The SRO under the strings of a stand-up bass or inside a kick drum will produce amazing sound. It is popular for drum overheads. A pair of SROs connected to a stereo recorder will provide excellent results for recording rehearsals and performances. The SRO is great for general studio use and is an exceptional value. It has no handling noise, no proximity effect, and is very forgiving in terms of placement.
A mounting clip is included with the microphone. This microphone has no removable parts.

Specifications:
- Frequency response: 10Hz to 20kHz ±2dB
- Polar Pattern: Omnidirectional (Fig. 4)
- Sensitivity: 8mV/Pa (Typical)
- Power Requirements: 48V Phantom, 10mA
- Peak Acoustic Input: 145dB SPL
- Output: XLR (Fig. 1)
- Output Impedance: 100Ω, balanced (50Ω ea. pin 2 & 3)
- Minimum Load: 600Ω btw. pins 2 & 3
- Noise: 27dBA equivalent
- Dimensions L x D 165 x 22 mm
(6.5 x .860 in.)
- Weight: 160g (.35lb)

SRO Earthworks  
by Damon from San Francisco,
February 01, 2005

“This conderser mic is IMPRESSIVE! I especially like the Omnidirectional polar pattern. I play flamenco guitar and was turned on to this by Spanish flamenco guitarist Vicente Amigo. He uses this for recording and you will know why when you try it out! It kicks any condenser mic's butt in its price range and $200 more! Get it. Earthworks are incredible.”